1. Field of the Invention
This invention relates to call simulators for PSTN-IP network telephone services and methods of operation. More particularly, the invention relates to a PSTN Call simulator and method of operation in testing PSTN to IP network telephone services for individual and group internet clients prior to availability of the telephone services.
2. Description of Prior Art
The introduction of PSTN-IP network based telephone services, e.g., call waiting, call forwarding, call back, etc., requires PSTN or IP network service providers to verify and validate these new services before on-line operations commence. The verification and validity involves generating hundreds of telephone calls per second and simulating thousands of IP network clients as individuals or group internet clients. What is needed to verify or validate a service is a call simulator, which simulates caller behavior to the telephone system in a test system for testing telephone services prior to the availability of the telephone services to the subscribers and clients.
Prior art related to PSTN Call simulators for testing telephone services includes the following:
U.S. Pat. No. 3,952,172 entitled xe2x80x9cTelephone Call simulatorxe2x80x9d, issued Apr. 20, 1976, discloses a telephone simulator, which includes a plurality of pseudo-subscriber circuits connected to subscriber lines. A plurality of pseudo junctures are connected to trunk lines. A number of detector circuits respond to line conditions, tones, circuit operations, data processing, and the like. A data processor uses this equipment to check incoming and outgoing calls to and from a public telephone network.
U.S. Pat. No. 4,238,649 entitled xe2x80x9cCall Simulatorxe2x80x9d, issued Dec. 9, 1980, discloses a traffic simulator for simulating calls switched through a tandem exchange by simulating both the calling and the answering exchange sides of signaling with the tandem exchange, and in which the progress of the call is split into a succession of phases during which a connection is set up through the tandem exchange, speech between subscribers is simulated, and the connection is cleared. A simulator comprises two independent modules, a calling side module connected to an incoming circuit terminating equipment of the exchange to simulate signaling between a calling exchange and the tandem exchange by its incoming circuit connected to the incoming terminating equipment and answering side module connected to an outgoing circuit terminating equipment of the exchange to simulate signaling between the tandem exchange and an answering exchange.
U.S. Pat. No. 5,065,422 entitled xe2x80x9cSubscriber Call Simulator Capable of Testing New Services of a Telephone Switching Systemxe2x80x9d, issued Nov. 12, 1991, discloses a subscriber call simulator connected to a telephone switching system through subscriber lines and acting as a plurality of pseudo-subscriber telephone sets. An input/output section, inputs control procedure information for the pseudo-subscriber""s telephone sets. Connected to the input/output section is a memorizing arrangement, which memorizes the control procedure information as stored information. By using the stored information, a control circuit controls the pseudo-subscriber""s telephone sets. The control procedure information comprises a control procedure program and correspondence information stored in a procedure program memory in a correspondence information memory, respectively, both of which act as the memorizing arrangement for automatically testing various new telephone services.
U.S. Pat. No. 5,621,670 entitled xe2x80x9cCommunication service simulator and a communication service specification verifying methodxe2x80x9d, issuedlfiled Apr. 15, 1997/Jul. 31, 1992describes a communication service simulator simulates communication service specification for a communication network having terminals and server nodes. The terminals of the communication network are registered in association with terminal data. When a called terminal has not been registered as terminal data during a simulation of a communication service specification, a terminal simulator registers the called terminal and the associated terminal data and displays the terminal data on a screen. A history regenerate/display unit displays on the screen any history of the content of a history storage unit. A simulation process controller copies a simulation process and separately executes and displays each of the processes when there is a branch, etc. in a communication service specification. During a simulation of a communication service specification, a sound output unit outputs a preselected sound from a first group of sounds when a preselected sound from a second group of sounds is received by a terminal specified by the identification information stored in a specified terminal identification information storage unit, and outputs a preselected sound from a third group of sounds, for a moment, in synchronism with the change on the screen of the terminal when the preselected sound from the second group of sounds is received by any terminal.
U.S. Pat. No. 3,952, 72 entitled xe2x80x9cTelephone call simulatorxe2x80x9d, issued/filed Apr. 20, 1976/Apr. 18, 1974 discloses a telephone simulator includes a plurality of pseudo subscriber circuits connected to subscriber lines. A plurality of pseudo junctures are connected to trunk lines. A number of detector circuits respond to line conditions, tones, circuit operations, data processing, and the like. A data processor uses these equipment to check incoming and outgoing calls to and from a public telephone network.
U.S. Pat. No. 4,021,624 entitled xe2x80x9cAutomatic call generatorxe2x80x9d, issued/filed May 3, 1977/Oct. 23, 1975 discloses an automatic call generator is connectable with the main distribution frame of a common control telephone system and monitors the operation of the system. To this end, the automatic call generator is connected to dedicated line and trunk circuit ports and attempts to place calls from one dedicated spot to another. If the system fails to terminate a call within a prescribed period of time, a malfunction is noted. Two malfunctions within a prescribed set of programs for monitoring the system cause a system alarm to be generated. The call generator also tests itself after proceeding through assigned programs for monitoring the system.
None of the prior art discloses a PSTN Call Simulator which generates call load, caller actions, test data capture and output for test case validation and verification of a network service executing across PSTN and IP network interfaces.
An object of the invention is a PSTN call simulator and method of operation for use in testing PSTN to IP network telephone services.
Another object is a PSTN call simulator and method of operation simulating thousands of IP network clients doing testing of PSTN-IP telephone services.
Another object is a call simulator and method of operation providing a mix of predictable client responses during testing of PSTN-IP telephone services.
Another object is a call simulator and method of operation, which provides separate and distinct simulated client actions during testing of PSTN-IP telephone services.
These and other objects, features and advantages are achieved in a telephone call simulator which generates telephone calls for large sets of subscribers in a PST-IP telephone service for purposes of validating various telephone services, e.g. call waiting, call forwarding, etc. available to subscribers of the telephone service. The telephone numbers of subscribers are grouped in different call processing actions and/or subscriber call behavior. The telephone numbers are stored in a test input data file. Test logic scripts are generated for each group of related telephone number and stored in a file, typically the test input data file. The test input data file is read by test assignment apparatus which assigns the test logic scripts to a call processing pool. The test logic scripts are also recorded in a test output data file. Call implementation apparatus in the pool executes random calling of each test logic script for the group of related telephone numbers and records the responses to the test logic scripts in the test output data file which validates the telephone services for the related telephone numbers.